No one would ever mistake the White House press briefing room for a courthouse or a confessional, so the blue curtains and official seal made an ironic backdrop this summer for President Obama’s impromptu homily on honesty in public life. “The truth of the matter is you can’t just make stuff up,” he told the scribblers who get paid to check his facts. “That’s one thing you learn as President of the United States. You get called in to account.” It was just what reporters wanted to hear, even if it was not exactly true.

At the time, Obama was speaking about a campaign ad from Mitt Romney that falsely claimed that the President had eliminated the work requirement for welfare. The ad was unmistakably deceptive. But just five minutes earlier in the very same press conference, Obama had offered some misdirection of his own. “Nobody accused Mr. Romney of being a felon,” he said. In fact, one of the President’s senior strategists, Stephanie Cutter, told reporters a month earlier that Romney was misrepresenting himself either to the American people or to securities regulators — “which is a felony,” she said.

Cutter’s was a conditional accusation but an accusation nonetheless, and at the time it allowed the Romney campaign to take its turn playing truth teller. “A reckless and unsubstantiated charge,” protested Romney campaign manager Matt Rhoades, who asked Obama to apologize. Of course, no apology was forthcoming. So the posturing got worse.

“You know, in the past, when people pointed out that something was inaccurate, why, campaigns pulled the ad,” Romney complained about Obama a few weeks later, without any apparent self-awareness. That was followed by Obama aides’ announcing that Romney’s campaign was built on a “tripod of lies” and that Republicans “really think that lying is a virtue.” Romney continued his protests, saying, “The challenge that I’ll have in the debate is that the President tends to — how shall I say it — to say things that aren’t true.”

So it goes in the world’s most celebrated democracy: another campaign day, another battle over the very nature of reality. Both of the men now running for the presidency claim that their opponent has a weak grasp of the facts and a demonstrated willingness to mislead voters. Both profess an abiding personal commitment to honesty and fair play. And both run campaigns that have repeatedly and willfully played the American people for fools, though their respective violations vary in scope and severity.

The rules for this back-and-forth were set in 1796, in the nation’s first contested presidential election, when John Adams’ supporters falsely charged Thomas Jefferson with atheism and loyalty to France while Jefferson’s forces made up fables about Adams’ monarchist ambitions. In the centuries since, campaigns have evolved into elaborate games of cops and robbers. Candidates and their supporters bend, twist and fabricate facts as much as they can without sparking a backlash. Reporters and opposing politicians do their best to run down the deceptions for voters.

But the perpetrators usually remain a step ahead of the cops. “It’s like the campaigns are driving 100 miles an hour on a highway with a posted speed limit of 60, but the patrol cars all have flats,” says Mark McKinnon, a Republican ad man for the presidential campaigns of George W. Bush and John McCain. “There was a quaint era in politics when we were held accountable for the truth and paid consequences for errors of fact. No more.”

Indeed, the 2012 campaign has witnessed a historic increase in fact-checking efforts by the media, with dozens of reporters now focused full time on sniffing out falsehood. Clear examples of deception fill websites, appear on nightly newscasts and run on the front pages of newspapers. But the truth squads have had only marginal success in changing the behavior of the campaigns and almost no impact on the outside groups that peddle unvarnished falsehoods with even less accountability. “We’re not going to let our campaign be dictated by fact checkers,” explained Neil Newhouse, Romney’s pollster, echoing his industry’s conventional wisdom.

Similarly, the so-called Truth Team for the Obama campaign has found itself in recurring spats with journalists brandishing facts. One of the most galling Obama deceptions, embedded in two television ads, asserts that Romney backed a bill outlawing “all abortion even in cases of rape and incest.” This is not true. Romney has consistently maintained, since becoming a pro-life politician in 2005, that he supports exceptions for rape and incest and to protect the life of the mother.